The document discusses political cartoons from the late 19th and early 20th centuries related to the Progressive Era in the United States. The cartoons portray industrialists like John D. Rockefeller as "robber barons" with monopolistic control depicted as an octopus, as well as political bosses asserting control over the U.S. Senate.

1. The Emergence of Modern America The Progressive Era

2. http://www.authentichistory.com/images/postcivilwar/cartoons/1900_jd_rockefeller_01.html

3. “ The Octopus,” 1904

4. “ The Bosses of the Senate,” 1890

5. “ The Robber Barons of Today,” 1889